System and Method for Semi-Persistent and Dynamic Scheduling and Discontinuous Reception Control

ABSTRACT

Methods of combining semi-persistent resource allocation and dynamic resource allocation are provided. Packets, such as VoIP packets, are transmitted on the uplink and downlink using respective semi-persistent resources. For each mobile device, awake periods and sleep periods are defined. The semi-persistent resources are aligned with the awake periods so that most of the time the mobile device can turn off its wireless access radio during the sleep periods. In addition, signalling to request, and to allocate, resources for additional packets are transmitted during the awake periods, and the resources allocated for the additional packets are within the awake windows.

RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application Ser.No. 60/944,383 filed on Jun. 15, 2007 which is incorporated herein byreference in its entirety.

FIELD OF THE APPLICATION

The application relates to wireless communication, and more particularlyto transmission scheduling for wireless communication.

BACKGROUND

With semi-persistent scheduling, for downlink VoIP (voice over IP(Internet Protocol)) communications to a mobile device, a periodic DL(downlink) transmission resource is allocated during a talk-spurt on thedownlink. The same resource is allocated each time. The allocation isturned on during each of the talk-spurts and off between talk-spurts. Inthis manner, explicit signalling to request an allocation, and to granta particular VoIP allocation is not required. Semi-persistent schedulingfor uplink VoIP communications from a mobile station is similar.

In addition to regular VoIP traffic, mobile devices also need theability to send and transmit larger IP packets. Such larger IP packetsare likely to be relatively infrequent compared to the frequency ofregular VoIP transmissions. Such packets might include uncompressed IPpackets, RTCP (Remote Transmit Power Control) packets, SIP/SDP (SessionInitiation Protocol/Session Description Protocol) packets, etc. Such IPpackets may be several hundreds of bytes in size and may have highpriority. In addition, larger packets may be required to transmit RRC(Radio Resource Control) Signalling messages. Examples of this arehandover related messages such as measurement reports. Some mobiledevices will also need the ability to deliver a mixed service in whichcase services in addition to VoIP need to be provided to the mobiledevice, such as e-mail, web browsing etc.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments will now be described with reference to the attacheddrawings in which:

FIG. 1 is a signalling diagram showing dynamic scheduling vs.semi-persistent scheduling;

FIG. 2 is a block diagram of an example wireless system;

FIG. 3 is a signalling diagram showing an awake period for dynamicscheduling in DRX (discontinuous reception);

FIG. 4 is a signalling diagram showing DRX and DTX (discontinuoustransmission) for uplink and downlink;

FIG. 5 is a state diagram having DRX and DTX transitions for VoIP;

FIGS. 6 and 7 are flowcharts of methods executed by a network to performcombined semi-persistent and dynamic scheduling;

FIG. 8 and 9 are flowcharts of methods executed by a mobile device toperform combined semi-persistent and dynamic scheduling; and

FIG. 10 is a block diagram of a mobile device.

DETAILED DESCRIPTION OF EMBODIMENTS

According to one broad aspect, the application provides a method in awireless network, the method comprising: for each mobile device of aplurality of mobile devices, in order to transmit to the mobile devicethe wireless network: a) transmitting downlink packets to the mobiledevice using a semi-persistent downlink transmission resource that isaligned with awake periods defined for the mobile device; b) for eachadditional downlink packet or sub-packet for the mobile device: i)dynamically allocating an additional downlink transmission resource totransmit the additional packet or sub-packet, the additional resourcebeing allocated to occur within one of the awake periods defined for themobile device; ii) during one of the awake periods defined for themobile device, transmitting signaling that defines the additionaldownlink transmission resource to transmit the additional packet orsub-packet; iii) during one of the awake periods defined for the mobiledevice, transmitting the additional downlink packet using the additionaldownlink resource.

According to another broad aspect, the application provides a method ina mobile device, the method comprising: controlling a receptioncapability of the mobile device during a plurality of awake periods anda plurality of sleep periods, the awake periods alternating in time withthe sleep periods, such that the reception capability is always onduring each of the awake periods, and the reception capability is offfor at least some of the sleep periods; receiving at the mobile devicedownlink packets on a semi-persistent downlink transmission resourcethat is aligned with the plurality of awake periods defined for themobile device; for each additional downlink packet or sub-packet for themobile device: i) during one of the awake periods, receiving signalingthat defines an additional downlink transmission resource to transmitthe additional downlink packet or sub-packet; ii) during one of theawake periods, receiving the additional downlink packet or sub-packet onthe additional downlink resource.

According to another broad aspect, the application provides a wirelessnetwork comprising: a semi-persistent scheduler for allocating asemi-persistent downlink resource that is aligned with awake periodsdefined for a mobile device for transmissions to the mobile device; atransmitter configured to: a) transmit downlink packets to the mobiledevice using the semi-persistent downlink transmission resourceallocated by the semi-persistent scheduler; b) for each additionaldownlink packet or sub-packet for the mobile device: i) during one ofthe awake periods defined for the mobile device, transmit signaling thatdefines a respective additional downlink transmission resource totransmit the additional packet or sub-packet; ii) during one of theawake periods defined for the mobile device, transmit the additionaldownlink packet using the respective additional downlink resource; adynamic scheduler for dynamically allocating the respective additionaldownlink transmission resource to transmit each additional packet orsub-packet, the additional resource being allocated to occur within oneof the awake periods defined for the mobile device.

According to another broad aspect, the application provides a mobiledevice comprising: a wireless access radio; a radio manager forcontrolling a reception capability of the wireless access radio during aplurality of awake periods and a plurality of sleep periods, the awakeperiods alternating in time with the sleep periods, such that thereception capability is always on during each of the awake periods, andthe reception capability is off for at least some of the sleep periods;the mobile device being configured to: receive downlink packets on asemi-persistent downlink transmission resource that is aligned with theplurality of awake periods defined for the mobile device; for eachadditional downlink packet or sub-packet for the mobile device: i)during one of the awake periods, receive signaling that defines anadditional downlink transmission resource to transmit the additionaldownlink packet or sub-packet; ii) during one of the awake periods,receive the additional downlink packet or sub-packet on the additionaldownlink resource.

Further aspects provide wireless networks, base stations, wirelessdevices that execute one or more of the methods summarized above ordetailed herein. Another embodiment provides a computer readable mediumhaving computer readable instructions for controlling the execution ofone or more of the methods summarized above or detailed herein.

Dynamic scheduling has been proposed to allow the dynamic allocation oftransmission resources, and the subsequent transmission of a largepacket using the dynamically allocated resources. Dynamic schedulinginvolves allocating a resource each time a packet is to be transmitted,and the resource can differ for each allocation. In a particularexample, see Applicant's co-pending U.S. Provisional Patent ApplicationNo. 60/944,376 filed on Jun. 15, 2007 and hereby incorporated byreference in its entirety.

In a specific example, a mobile device supporting VoIP with dynamicscheduling monitors layer 1 CCEs (Control Channel Elements) continuouslyfor dynamic scheduling grants even though the mobile device might beonly involved in a VoIP session. LTE (Long Term Evolution) refers toCCEs, but the term has more general application to mean simply controlinformation.

As indicated above, a mobile device may support VoIP with dynamicscheduling by monitoring layer 1 CCEs continuously for dynamicscheduling grants. Unfortunately, this might waste battery power for themobile device, particularly when there are very few or even no dynamicscheduling grants for the mobile device.

Referring now to FIG. 1, shown is a signalling diagram showing dynamicscheduling vs. semi-persistent scheduling. Time is on the horizontalaxis. Shown is a periodic semi-persistent allocation 50. For VoIPtransmission, this can for example include a resource allocated every 20ms. In addition, there is a regular set of layer 1 CCEs 52 that aretransmitted. In the illustrated example, these are transmitted in every1 ms but it is to be clearly understood that the other resourceallocation periods and CCE periods are possible. This example assumesdownlink transmission, but a similar approach applies to uplinktransmission. During the periods that occur between talk-spurts, (alsoreferred to as “silence” or “silence periods”), the transmitter andreceiver can be turned off. During a talk-spurt period (also referred toas a period that VoIP transmission is “active”, or “active mode”), ifnot for dynamic scheduling, the mobile device could wake up regularly toblind-detect its data in the semi-persistently allocated resource at thepre-defined interval (e.g. every 20 ms) while entering a “sleeping” modeat other times. This can also be referred to as DRX (discontinuousreception). This simply means that the receive capability of the mobiledevice's radio is basically turned off while the mobile device is insleep mode thereby resulting in battery life extension. However, giventhat other data may arrive via dynamic scheduling by any of the CCEs 52,the mobile device needs to monitor the CCEs of all sub-frames. In thefull dynamic scheduling case there is no discontinuous transmission(DTX) or DRX and this rules out the possibility of using DRX since themobile device needs to continue monitoring the layer 1 CCEs for dynamicscheduling grants. This is not power efficient and leads to lowerbattery charge lifetimes.

To efficiently support the DRX in VoIP active mode in order to reducethe battery power consumption, systems and methods are provided forcombining semi-persistent scheduling for VoIP with a schedulingcapability for additional packet transmission.

System for Semi-persistent Scheduling and DRX Control

Referring now to FIG. 2, shown is a block diagram of an example wirelesssystem 40. The wireless system 40 has a wireless network 28 and a mobiledevice 10. The wireless system also has other mobile devices 30.

The mobile device 10 has a wireless access radio 12, a processor 16 anda radio manager 14 that is responsible for controlling the wirelessaccess radio 12. There may be additional components not shown. Thewireless network 28 has a scheduler 32 that encompasses asemi-persistent scheduler 34 and a dynamic scheduler 36. The wirelessnetwork 28 has components such as base stations (not shown) forproviding wireless access. The scheduler 32 may reside in the basestations or elsewhere in the network 28. In LTE, the scheduler istypically in the eNB (enhanced NodeB). In the examples that follow, itis assumed scheduler 32 is part of a base station.

In the illustrated example, the scheduler 32 and radio manager 14 areimplemented as software and executed on processors forming part of thenetwork 28 and mobile device 10 respectively. However, more generally,these functions may be implemented as software, hardware, firmware, orany appropriate combination thereof.

Furthermore, it is to be understood that the wireless network would haveany appropriate components suitable for a wireless network 28. Note thatthe wireless network may include wires that interconnect networkcomponents in addition to components for providing wirelesscommunication with mobile devices. The components of the wirelessnetwork are implementation specific and may depend on the type ofwireless network. There are many possibilities for the wireless network.The wireless network might for example be a UMTS network or any cellularnetwork that uses semi-persistent resource assignment.

In operation, the mobile device 10 communicates with the wirelessnetwork 28 over a wireless connection 19 between the mobile device 10and the wireless network 28. The communication with the wireless network28 includes VoIP packet transmission and additional packet transmission.The semi-persistent scheduler 34 is responsible for making an initialresource allocation for a VoIP service to the mobile device 10. Thisincludes an uplink semi-persistent allocation and a downlinksemi-persistent allocation. The semi-persistent scheduler 34 is alsoresponsible for keeping track of whether there is a talk-spurt inprogress for the uplink and/or the downlink and for turning on and offthe uplink and/or downlink allocation accordingly. While de-allocated,the semi-persistently allocated resources can be made available forother purposes. Note that the form of the transmission resources thatare being allocated is implementation specific. Particular examples ofresources that might be used include OFDM resources and CDMA resources.The dynamic scheduler 36 is responsible for making resource allocationsfor additional packet transmissions that are not accommodated by thesemi-persistent allocation. The additional packets may be related toand/or form part of the VoIP service, or be unrelated to the VoIPservice.

The radio manager 14 controls the on/off state of the wireless accessradio 12. In some wireless access radios, the transmitter and receivermust be turned on and off together, and as such, uplink and downlinkscheduling must be coordinated to allow the wireless access radio to beturned off. In some wireless access radios, receive and transmitcapabilities can be independently turned off.

In some embodiments, the network 28 sends DRX control signalling to themobile device 10 that sets a repeating pattern that has a DRX periodhaving an awake period and a sleep period. An example could be: DRXperiod is 20 ms with sleep period equal to 15 ms and awake period equalto 5 ms. During the awake period, the mobile device turns its receiveron. During the sleep period, the mobile device turns its receiver off.This signalling might be sent at the start of each VoIP session, forexample.

Referring now to FIG. 3, shown is a signalling diagram showing anexample of semi-persistent and dynamic scheduling and DRX. Shown is asemi-persistent allocation 60 available for semi-persistent VoIP DLtransmissions. In addition, there are layer 1 CCEs 62 for signallingdynamic allocations so as to allow the transmission of additionalpackets. This represents the transmissions from the base station. Themobile device receiving the transmissions alternates between being in anawake state and a sleep state. The mobile station is in an awake stateduring awake periods 64 and the mobile device is nominally in a sleepstate during sleep periods 66. The first thing that the scheduler in thenetwork needs to do is to ensure that the semi-persistent allocation 60coincides with the awake periods 64. In addition, each awake period 64is longer than the minimum necessary to transmit the VoIPsemi-persistent allocation. There is also the opportunity to dynamicallyschedule (as signalled on one of the CCEs 62) and transmit an additionalpacket. An example of this is shown where a dynamic allocation issignalled in CCE 62-1. Additional packet 67 is shown transmittedimmediately following CCE 62-1. The additional packet might for examplebe an RTCP (radio transmission control protocol) packet, SIP/SDP(session initiation protocol, session description protocol) packet, or apacket that has not undergone IP\UDP\RTP (internet protocol\userdatagram protocol\radio transmission protocol) header compression, etc.While the mobile device is in the sleep state, it operates in a reducedpower consumption mode, by turning off reception capability and/or byturning off its reception and transmission capabilities. In thisexample, the network has scheduled the additional packet 67 to betransmitted during one of the awake periods 64, and signals this using aCCE 62-1 that is transmitted during one of the awake periods 64. Moregenerally, when the mobile device wakes up after a sleep period, themobile device will not only blind detect its own VoIP data on thesemi-persistently allocated resource 60, but also will detect, moregenerally attempt to detect, all the CCEs during the awake periods.

In some embodiments, after the mobile device determines that there willbe a dynamically allocated resource for the mobile device as signalledin one of the CCEs in a given awake period, the mobile device does notmonitor further CCEs during that awake period.

In some embodiments, the base station will transmit signalling toconfigure the mobile device with this DRX behaviour, and thereafter allthe dynamic scheduling will occur only in this “awake period”. Forexample, the mobile device may sleep every 15 ms, and then wake up for 5ms to continuously receive data. The behaviour repeats with a period of20 ms. During the 5 ms awake period, the mobile device will blind-detectits VoIP data on the semi-persistently allocated resource and also themobile device will monitor all the CCEs. The base station understandsthis DRX configuration and will schedule the associated dynamic packetssuch as RTCP, SIP/SDP, etc, during this 5 ms awake period. In someimplementations, when a retransmission occurs, the mobile device will bein continuous mode by default.

The radio manager 14 controls the operation of the wireless access radio12 such that a reception capability is powered on during the awakeperiods, and off for at least some of the sleep periods. As describedbelow, it may be necessary for the reception capability to be on duringsome of the sleep periods to allow for retransmissions.

The signalling for dynamic scheduling is performed during the awakeperiods. In addition, the actual resources allocated for the additionalpacket transmissions are scheduled to occur during the awake periods.

In some embodiments, when it becomes necessary for a retransmission, themobile device enters a continuous mode of operation. While in continuousmode, the mobile device continuously receives and monitors the downlinkchannel and does not turn off reception capability. Further, in someembodiments, if a mixed service needs to be provided to the mobiledevice, this is used as a trigger to also enable the continuous modeoperation. This trigger may be dependent on the traffic QoS of theservice being added.

Uplink Semi-Persistent Alignment with Downlink for DRX

The above discussion is focussed on downlink transmission from the basestation to the mobile device and on the mobile device's ability to turnoff its reception capability during the sleep period. However, somemobile devices are not able to turn off only their reception capabilitywhile leaving on a transmit capability or vice versa. Thus, for suchdevices in order to fully realize the benefit of having an awake periodand a sleep period for reception, uplink transmissions should are alsoscheduled to align with these awake periods and sleep periods. Anexample of this is shown in FIG. 4. In FIG. 4, the downlink transmissionis indicated at 78 and this is basically the same as that describedabove with reference to FIG. 3, and this will not be described again.The uplink transmissions are generally indicated at 80. Here, there is asemi-persistent allocation 82 for VoIP UL transmissions. These arescheduled to occur during the periods 64 that the mobile device isawake. In addition, an uplink control channel is indicated at 84. In theillustrated example, this occurs every 1 ms. The mobile device onlytransmits the uplink control channel during the awake periods 64. Themobile device can use the uplink control channel to make requests foradditional resources. By scheduling the uplink semi-persistenttransmission and downlink semi-persistent transmission to occur duringthe same awake period, the mobile device can realize much more efficientDRX and DTX (discontinuous reception and discontinuous transmission)behaviour. In the example of FIG. 4, the mobile device is configured tosleep every 15 ms, and then wake up for 5 ms. During this 5 ms awakeperiod, the mobile device will receive DL semi-persistent reception ifavailable (during a DL talk-spurt) and make an uplink semi-persistenttransmission if available (during an UL talk-spurt). The mobile devicewill also detect all the DL grants and possibly make uplink additionalresource requests.

In case of retransmissions (either the DL or the UL), the mobile devicewill enter the continuous mode by default. Note that both the uplink anddownlink VoIP semi-persistent allocations have the same trafficcharacteristics (every 20 ms), hence the base station can easily alignthe semi-persistent allocation for the DL and UL.

With this approach, even in the active mode (talk-spurt in progress onthe uplink or the downlink), the mobile device can be in DRX and DTXmode most of the time. The mobile device monitors the Layer 1 CCEs onthe downlink only during the awake period, and may request moreresources on the uplink. This can save battery power for the mobiledevice. Considering that an additional IP packet delivery during a VoIPsession may be infrequent, the battery saving could be significant. Adrawback is that the dynamic scheduling could be delayed by anadditional 10 ms on average.

Referring now to FIG. 5, shown is a state diagram having DRX/DTX statetransitions for VoIP. It is noted that when there is no uplink anddownlink transmission (i.e. silence in both directions), the mobiledevice only needs to monitor the DL CCEs for dynamic scheduling duringthe awake period. There are two main states. The first main state is theUE sleep state 100 and the second main state is the UE awake state 102.For the illustrated example, it is assumed that the sleep state 100lasts 15 ms and the awake state lasts 5 ms and can be extended, but thisis again implementation specific. Steps 102-1 and 102-2 are executed fordownlink communication during the awake state 102. Step 102-1 involvesreceiving all of the downlink CCEs and processing them to identifydownlink dynamic scheduling if present. This is done irrespective ofwhether or not there is any downlink VoIP transmission. In the eventthat a downlink talk-spurt is ongoing, then step 102-2 is also executed.This involves receiving the VoIP payload in the semi-persistentresource. Steps 102-3 and 102-4 are executed in respect of uplinktransmissions. 102-3 is only executed if the mobile device determinesthat it needs a dynamic allocation for uplink transmission. Step 102-3involves making a resource request, for example over a random accesschannel, and monitoring the downlink CCE for uplink grants. In addition,if there is an uplink talk-spurt in progress, then the mobile devicewill execute step 102-4 which involves transmitting the uplink VoIPpayload in the semi-persistent resource for uplink transmission.

The above description has focussed on applications where the trafficthat is sent using the semi-persistent allocation is VoIP traffic. Moregenerally, the same methods and systems can be applied to combine thetransmission and scheduling of traffic of any type on asemi-persistently allocated resource with the transmission andscheduling of traffic that uses dynamic resource allocations.

In the above examples, CCEs spaced by 1 ms are used for the downlinkcontrol channel. More generally, the downlink control channel can takeany form. The only limitation is that dynamic allocations for a givenmobile device take place during awake periods for the mobile device.Similarly, at least in the figures, the uplink control channel has beendepicted as a random access channel that is available at intervalsspaced by 1 ms. More generally, the uplink control channel forrequesting additional resource allocations can come in any form. Theonly limitation is that requests for dynamic allocations for uplinktransmission from a given mobile device will need to be transmittedduring awake periods for the mobile device.

In some embodiments, the additional packet is transmitted as a series ofone or more sub-packets formed by segmenting the additional packet.These are subject to reassembly at the receiver.

Methods for Semi-persistent Scheduling and DRX Control Executed by theWireless Network

A method in a wireless network for performing downlink transmission tomobile devices will be described with reference to the flowchart of FIG.6. These steps are performed for each mobile device being providedwireless access on a semi-persistent downlink transmission resource. Themethod begins at step 6-1 with transmitting downlink packets to themobile device using a semi-persistent downlink transmission resourcethat is aligned with awake periods defined for the mobile device. Thesecan be downlink VoIP packets during a downlink talk-spurt for a VoIPsession involving the mobile device or otherwise. Steps 6-2,6-3,6-4 areexecuted for each additional downlink packet for the mobile device. Instep 6-2, the wireless network dynamically allocates an additionaldownlink transmission resource to transmit the additional packet, theadditional resource being allocated to occur within one of the awakeperiods defined for the mobile device. In step 6-3, during one of theawake periods defined for the mobile device, the wireless networktransmits signaling that defines the additional downlink transmissionresource to transmit the additional packet. In step 6-4, during one ofthe awake periods defined for the mobile device, the wireless networktransmits the additional downlink packet using the additional downlinkresource. In some embodiments, all of the steps are performed in a basestation. In other embodiments, certain steps, for example the dynamicallocation, can be performed in another network element if centralizedscheduling is performed.

A method in a wireless network for performing uplink reception frommobile devices will be described with reference to the flowchart of FIG.7. These steps are performed for each mobile device being providedwireless access on a semi-persistent downlink transmission resource. Themethod begins with receiving uplink packets from the mobile device usinga semi-persistent uplink transmission resource that is aligned with theawake periods defined for the mobile device. These can be VoIP packetsduring an uplink talk-spurt for a VoIP session involving the mobiledevice or otherwise. Steps 7-2, 7-3, 7-4 and 7-5 are performed for eachadditional each additional uplink packet for the mobile device. In step7-2, during one of the awake periods, the wireless network receives arequest for an additional uplink transmission resource to transmit theadditional uplink packet. In step 7-3, the wireless network dynamicallyallocates the additional uplink transmission resource such that theadditional uplink transmission resource occurs during one of the awakeperiods defined for the mobile device. In step 7-4, during one of theawake periods defined for the mobile device, the wireless networktransmits signaling that defines the additional uplink allocation. Instep 7-5, the wireless network receives the additional uplink packetusing the additional uplink transmission resource.

In some embodiments, the wireless network transmits signaling to eachmobile device that defines the awake periods and that defines sleepperiods of that mobile device and/or that defines the semi-persistentuplink and/or downlink transmission resource of that mobile device. ForVoIP, the signaling to define the semi-persistent resources might bedone at the start of each VoIP session. Such signaling can be performedon a channel that is dedicated to each mobile device, or using abroadcast channel containing such signaling for multiple devices.

Methods for Semi-Persistent Scheduling and DRX Control Executed by theMobile Device

Referring now to FIG. 8, a method of receiving downlink transmissionexecuted by a mobile device will now be described. The method begins atstep 8-1 with the mobile device controlling a reception capability ofthe mobile device during a plurality of awake periods and a plurality ofsleep periods, the awake periods alternating in time with the sleepperiods, such that the reception capability is always on during each ofthe awake periods, and the reception capability is off for at least someof the sleep periods. On a nominal basis, typically the receptioncapability will be off for every sleep period. At step 8-2, the mobiledevice receives downlink packets on a semi-persistent downlinktransmission resource that is aligned with a plurality of awake periodsdefined for the mobile device. These can be VoIP downlink packets duringa downlink talk-spurt for a VoIP session involving the mobile device, orotherwise. Steps 8-3 and 8-4 are performed for each additional downlinkpacket for the mobile device. In step 8-3, during one of the awakeperiods, the mobile device receives signaling that defines an additionaldownlink transmission resource to transmit the additional packet, theadditional downlink transmission resource being allocated to occurwithin one of the awake periods defined for the mobile device. In step8-4, during one of the awake periods, the mobile device receives theadditional downlink packet on the additional downlink resource.

The mobile device may receive signaling that defines the awake periodsand the sleep periods of the mobile device and/or that defines thesemi-persistent downlink transmission resource of that mobile device.This may take place over a respective dedicated channel for the mobiledevice or over a broadcast channel containing signaling information forthe mobile device and other mobile devices.

Referring now to FIG. 9, a method of transmitting uplink transmissionsexecuted by a mobile device will now be described. The method begins atstep 9-1 with controlling a transmission capability of the mobile devicesuch that the transmission capability is on during all of the awakeperiods and such that the transmission capability is off for at leastsome of the sleep periods. In step 9-2, the mobile device transmitsuplink packets (VoIP packets or otherwise) using a semi-persistentuplink transmission resource that is aligned with the awake periodsdefined for the mobile device. Steps 9-3, 9-4, 9-5 are executed for eachadditional uplink packet for the mobile device. In step 9-3, during oneof the awake periods defined for the mobile device, the mobile devicetransmits a request for an additional uplink transmission resource totransmit the additional uplink packet. In step 9-4, during one of theawake periods, the mobile device receives signaling that defines theadditional uplink transmission resource, the additional uplinktransmission resource being allocated to occur during one of the awakeperiods defined for the mobile device. In step 9-5, during one of theawake periods, the mobile device transmits the additional uplink packetusing the additional uplink transmission resource.

The mobile device may receive signaling that defines the semi-persistentuplink resource. In some embodiments, the request for an additionaluplink allocation is transmitted using a contention based random accesschannel.

In some embodiments, mobile devices have radios that feature atransmitter and a receiver. While the radio is on, the receivercapability is on, and the receiver will be actively attempting toprocess signals received on the mobile device's antenna(s). There is notnecessarily content for the given mobile device all the time that thereceiver is on, but the receiver is consuming power nonetheless for thattime period. In addition, while the radio is on, the mobile device isable to transmit. However, so long as the mobile device does not havesomething to transmit, there is no active transmission taking place, andas such little or no transmit power consumption occurs until there is anactive transmission.

In embodiments referring to NACK/ACK transmission, the particularNACK/ACK scheme employed is implementation specific. Some embodimentsemploy an ACK only scheme; other embodiments employ a NACK only scheme,while others use both ACKs and NACKs.

Another Mobile Device

Referring now to FIG. 10, shown is a block diagram of another mobiledevice that may implement any of the mobile device methods describedherein. The mobile device 101 is shown with specific components forimplementing features similar to those of the mobile device 10 of FIG.2. It is to be understood that the mobile device 101 is shown with veryspecific details for example purposes only.

A processing device (a microprocessor 128) is shown schematically ascoupled between a keyboard 114 and a display 126. The microprocessor 128may be a specific example of the processor with features similar tothose of the processor 16 of the mobile device 10 shown in FIG. 2. Themicroprocessor 128 controls operation of the display 126, as well asoverall operation of the mobile device 101, in response to actuation ofkeys on the keyboard 114 by a user.

The mobile device 101 has a housing that may be elongated vertically, ormay take on other sizes and shapes (including clamshell housingstructures). The keyboard 114 may include a mode selection key, or otherhardware or software for switching between text entry and telephonyentry.

In addition to the microprocessor 128, other parts of the mobile device101 are shown schematically. These include: a communications subsystem170; a short-range communications subsystem 103; the keyboard 114 andthe display 126, along with other input/output devices including a setof LEDs 104, a set of auxiliary I/O devices 106, a serial port 108, aspeaker 111 and a microphone 112; as well as memory devices including aflash memory 116 and a Random Access Memory (RAM) 118; and various otherdevice subsystems 120. The mobile device 101 may have a battery 121 topower the active elements of the mobile device 101. The mobile device101 is in some embodiments a two-way radio frequency (RF) communicationdevice having voice and data communication capabilities. In addition,the mobile device 101 in some embodiments has the capability tocommunicate with other computer systems via the Internet.

Operating system software executed by the microprocessor 128 is in someembodiments stored in a persistent store, such as the flash memory 116,but may be stored in other types of memory devices, such as a read onlymemory (ROM) or similar storage element. In addition, system software,specific device applications, or parts thereof, may be temporarilyloaded into a volatile store, such as the RAM 118. Communication signalsreceived by the mobile device 101 may also be stored to the RAM 118.

The microprocessor 128, in addition to its operating system functions,enables execution of software applications on the mobile device 101. Apredetermined set of software applications that control basic deviceoperations, such as a voice communications module 130A and a datacommunications module 130B, may be installed on the mobile device 101during manufacture. In addition, a personal information manager (PIM)application module 130C may also be installed on the mobile device 101during manufacture. The PIM application is in some embodiments capableof organizing and managing data items, such as e-mail, calendar events,voice mails, appointments, and task items. The PIM application is alsoin some embodiments capable of sending and receiving data items via awireless network 110. In some embodiments, the data items managed by thePIM application are seamlessly integrated, synchronized and updated viathe wireless network 110 with the device user's corresponding data itemsstored or associated with a host computer system. As well, additionalsoftware modules, illustrated as another software module 130N, may beinstalled during manufacture. One or more of the modules130A,130B,130C,130N of the flash memory 116 can be configured forimplementing features similar to those of the radio manager 14 of themobile device 10 shown in FIG. 2.

Communication functions, including data and voice communications, areperformed through the communication subsystem 170, and possibly throughthe short-range communications subsystem 103. The communicationsubsystem 170 includes a receiver 150, a transmitter 152 and one or moreantennas, illustrated as a receive antenna 154 and a transmit antenna156. In addition, the communication subsystem 170 also includes aprocessing module, such as a digital signal processor (DSP) 158, andlocal oscillators (LOs) 160. The communication subsystem 170 having thetransmitter 152 and the receiver 150 is an implementation of a specificexample of the wireless access radio 12 of the mobile device 10 shown inFIG. 2. The specific design and implementation of the communicationsubsystem 170 is dependent upon the communication network in which themobile device 101 is intended to operate. For example, the communicationsubsystem 170 of the mobile device 101 may be designed to operate withthe Mobitex™, DataTAC™ or General Packet Radio Service (GPRS) mobiledata communication networks and also designed to operate with any of avariety of voice communication networks, such as Advanced Mobile PhoneService (AMPS), Time Division Multiple Access (TDMA), Code DivisionMultiple Access (CDMA), Personal Communications Service (PCS), GlobalSystem for Mobile Communications (GSM), etc. The communication subsystem170 may also be designed to operate with an 802.11 Wi-Fi network, and/oran 802.16 WiMAX network. Other types of data and voice networks, bothseparate and integrated, may also be utilized with the mobile device101.

Network access may vary depending upon the type of communication system.For example, in the Mobitex™ and DataTAC™ networks, mobile devices areregistered on the network using a unique Personal Identification Number(PIN) associated with each device. In GPRS networks, however, networkaccess is typically associated with a subscriber or user of a device. AGPRS device therefore typically has a subscriber identity module,commonly referred to as a Subscriber Identity Module (SIM) card, inorder to operate on a GPRS network.

When network registration or activation procedures have been completed,the mobile device 101 may send and receive communication signals overthe communication network 110. Signals received from the communicationnetwork 110 by the receive antenna 154 are routed to the receiver 150,which provides for signal amplification, frequency down conversion,filtering, channel selection, etc., and may also provide analog todigital conversion. Analog-to-digital conversion of the received signalallows the DSP 158 to perform more complex communication functions, suchas demodulation and decoding. In a similar manner, signals to betransmitted to the network 110 are processed (e.g., modulated andencoded) by the DSP 158 and are then provided to the transmitter 152 fordigital to analog conversion, frequency up conversion, filtering,amplification and transmission to the communication network 110 (ornetworks) via the transmit antenna 156.

In addition to processing communication signals, the DSP 158 providesfor control of the receiver 150 and the transmitter 152. For example,gains applied to communication signals in the receiver 150 and thetransmitter 152 may be adaptively controlled through automatic gaincontrol algorithms implemented in the DSP 158.

In a data communication mode, a received signal, such as a text messageor web page download, is processed by the communication subsystem 170and is input to the microprocessor 128. The received signal is thenfurther processed by the microprocessor 128 for an output to the display126, or alternatively to some other auxiliary I/O devices 106. A deviceuser may also compose data items, such as e-mail messages, using thekeyboard 114 and/or some other auxiliary I/O device 106, such as atouchpad, a rocker switch, a thumb-wheel, or some other type of inputdevice. The composed data items may then be transmitted over thecommunication network 110 via the communication subsystem 170.

In a voice communication mode, overall operation of the device issubstantially similar to the data communication mode, except thatreceived signals are output to a speaker 111, and signals fortransmission are generated by a microphone 112. Alternative voice oraudio I/O subsystems, such as a voice message recording subsystem, mayalso be implemented on the mobile device 101. In addition, the display126 may also be utilized in voice communication mode, for example, todisplay the identity of a calling party, the duration of a voice call,or other voice call related information.

The short-range communications subsystem 103 enables communicationbetween the mobile device 101 and other proximate systems or devices,which need not necessarily be similar devices. For example, theshort-range communications subsystem may include an infrared device andassociated circuits and components, or a Bluetooth™ communication moduleto provide for communication with similarly-enabled systems and devices.

Numerous modifications and variations of the present application arepossible in light of the above teachings. It is therefore to beunderstood that within the scope of the appended claims, the applicationmay be practised otherwise than as specifically described herein.

1. A method in a wireless network, the method comprising: for eachmobile device of a plurality of mobile devices, in order to transmit tothe mobile device the wireless network: a) transmitting downlink packetsto the mobile device using a semi-persistent downlink transmissionresource that is aligned with awake periods defined for the mobiledevice; b) for each additional downlink packet or sub-packet for themobile device: i) dynamically allocating an additional downlinktransmission resource to transmit the additional packet or sub-packet,the additional resource being allocated to occur within one of the awakeperiods defined for the mobile device; ii) during one of the awakeperiods defined for the mobile device, transmitting signaling thatdefines the additional downlink transmission resource to transmit theadditional packet or sub-packet; iii) during one of the awake periodsdefined for the mobile device, transmitting the additional downlinkpacket using the additional downlink resource.
 2. The method of claim 1wherein: transmitting downlink packets to the mobile device using asemi-persistent downlink transmission resource that is aligned withawake periods defined for the mobile device comprises transmittingdownlink VoIP packets during a downlink talk-spurt for a VoIP sessioninvolving the mobile device.
 3. The method of claim 1 furthercomprising: transmitting signaling to each mobile device that definesthe awake periods and that defines sleep periods of that mobile device.4. The method of claim 1 further comprising: transmitting signaling toeach mobile device that defines the semi-persistent downlinktransmission resource of that mobile device.
 5. The method of claim 1further comprising: transmitting a broadcast channel containingsignaling information; wherein for each mobile device, transmittingsignaling during one of the awake periods defined for the mobile devicethat defines the downlink resource for the additional downlink packetcomprises transmitting the signaling information on the broadcastchannel during one of the awake periods defined for that mobile device.6. The method of claim 1 further comprising: for each mobile device ofthe plurality of mobile devices, in order to receive from the mobiledevice, the wireless network: c) receiving uplink packets from themobile device using a semi-persistent uplink transmission resource thatis aligned with the awake periods defined for the mobile device; d) foreach additional uplink packet or sub-packet for the mobile device: i)during one of the awake periods, receiving a request for an additionaluplink transmission resource to transmit the additional uplink packet orsub-packet; ii) dynamically allocating the additional uplinktransmission resource such that the additional uplink transmissionresource occurs during one of the awake periods defined for the mobiledevice; iii) during one of the awake periods defined for the mobiledevice, transmitting signaling that defines the additional uplinkallocation; iv) receiving the additional uplink packet or sub-packetusing the additional uplink transmission resource.
 7. The method ofclaim 6 wherein receiving uplink packets from the mobile device using asemi-persistent uplink transmission resource that is aligned with theawake periods defined for the mobile device comprises receiving uplinkVoIP packets during an uplink talk-spurt for a VoIP session involvingthe mobile device.
 8. The method of claim 6 further comprising: for eachmobile device, transmitting signaling to the mobile device that definesthe semi-persistent uplink resource for the mobile device.
 9. A methodin a mobile device, the method comprising: controlling a receptioncapability of the mobile device during a plurality of awake periods anda plurality of sleep periods, the awake periods alternating in time withthe sleep periods, such that the reception capability is always onduring each of the awake periods, and the reception capability is offfor at least some of the sleep periods; receiving at the mobile devicedownlink packets on a semi-persistent downlink transmission resourcethat is aligned with the plurality of awake periods defined for themobile device; for each additional downlink packet or sub-packet for themobile device: i) during one of the awake periods, receiving signalingthat defines an additional downlink transmission resource to transmitthe additional downlink packet or sub-packet; ii) during one of theawake periods, receiving the additional downlink packet or sub-packet onthe additional downlink resource.
 10. The method of claim 9 whereinreceiving downlink packets on a semi-persistent downlink transmissionresource comprises receiving VoIP downlink packets during a downlinktalk-spurt for a VoIP session involving the mobile device.
 11. Themethod of claim 10 wherein controlling a reception capability of themobile device during a plurality of awake periods and a plurality ofsleep periods, the awake periods alternating in time with the sleepperiods, such that the reception capability is always on during each ofthe awake periods, and the reception capability is off for at least someof the sleep periods comprises: turning off reception capability duringeach of the plurality of sleep periods, unless a retransmission isexpected.
 12. The method of claim 9 further comprising: receivingsignaling that defines the awake periods and the sleep periods of themobile device.
 13. The method of claim 9 further comprising: receivingsignaling that defines the semi-persistent downlink transmissionresource of that mobile device.
 14. The method of claim 9 furthercomprising: receiving a broadcast channel containing signalinginformation for the mobile device and other mobile devices; whereinreceiving signaling during one of the awake periods that defines thedownlink resource for the additional downlink packet or sub-packetcomprises receiving the signaling information on the broadcast channelduring one of the awake periods for that mobile device.
 15. The methodof claim 14 further comprising: during every awake period, monitoringthe broadcast channel for signaling information indicating a dynamicallocation of a downlink resource for an additional downlink packet orsub-packet.
 16. The method of claim 9 further comprising: controlling atransmission capability of the mobile device such that the transmissioncapability is on during all of the awake periods and such that thetransmission capability is off for at least some of the sleep periods;transmitting uplink packets from the mobile device using asemi-persistent uplink transmission resource that is aligned with theawake periods defined for the mobile device; for each additional uplinkpacket or sub-packet for the mobile device: i) during one of the awakeperiods defined for the mobile device, transmitting a request for anadditional uplink transmission resource to transmit the additionaluplink packet or sub-packet; ii) during one of the awake periods,receiving signaling that defines the additional uplink allocation, theadditional uplink allocation being allocated to occur during one of theawake periods defined for the mobile device; iii) during one of theawake periods, transmitting the additional uplink packet or sub-packetusing the additional uplink transmission resource.
 17. The method ofclaim 16 wherein: transmitting uplink packets from the mobile deviceusing a semi-persistent uplink transmission resource that is alignedwith the awake periods defined for the mobile device comprisestransmitting VoIP uplink packets during an uplink talk spurt for a VoIPsession involving the mobile device.
 18. The method of claim 17 furthercomprising: receiving signaling that defines the semi-persistent uplinktransmission resource.
 19. The method of claim 17 wherein for eachadditional uplink packet or sub-packet transmitting a request for anadditional uplink transmission resource comprises transmitting therequest using a contention based random access channel.
 20. A wirelessnetwork comprising: a semi-persistent scheduler for allocating asemi-persistent downlink resource that is aligned with awake periodsdefined for a mobile device for transmissions to the mobile device; atransmitter configured to: a) transmit downlink packets to the mobiledevice using the semi-persistent downlink transmission resourceallocated by the semi-persistent scheduler; b) for each additionaldownlink packet or sub-packet for the mobile device: i) during one ofthe awake periods defined for the mobile device, transmit signaling thatdefines a respective additional downlink transmission resource totransmit the additional packet or sub-packet; ii) during one of theawake periods defined for the mobile device, transmit the additionaldownlink packet using the respective additional downlink resource; adynamic scheduler for dynamically allocating the respective additionaldownlink transmission resource to transmit each additional packet orsub-packet, the additional resource being allocated to occur within oneof the awake periods defined for the mobile device.
 21. A mobile devicecomprising: a wireless access radio; a radio manager for controlling areception capability of the wireless access radio during a plurality ofawake periods and a plurality of sleep periods, the awake periodsalternating in time with the sleep periods, such that the receptioncapability is always on during each of the awake periods, and thereception capability is off for at least some of the sleep periods; themobile device being configured to: receive downlink packets on asemi-persistent downlink transmission resource that is aligned with theplurality of awake periods defined for the mobile device; for eachadditional downlink packet or sub-packet for the mobile device: i)during one of the awake periods, receive signaling that defines anadditional downlink transmission resource to transmit the additionaldownlink packet or sub-packet; ii) during one of the awake periods,receive the additional downlink packet or sub-packet on the additionaldownlink resource.